Washington - Boeing released a video featuring the foldable wings of future 777X in its Everett factory, a first in civil aviation. The maiden flight of the aircraft is scheduled for next year. (airlinerwatch.com) Daha Fazlası...

I would have thought folding down would fail safer than folding up due to lift? At the moment the locking mechanism is constantly being strained by the lift experienced, which is far greater than the weight of the wing (one would hope xD).

I'm going by memory, but the tips are around 10' each, and add up to a reduction in width of something like 22' overall.

That may not sound like much, but it's enough to allow the planes to fit into gates already built at airports around the world. Lets the plane land & accommodate passengers at more places and saves the airports money in construction to widen the gates.